The present invention relates to a magnetic recording medium used in, for example, a magnetic disk apparatus, and to a production process for the medium.
A conventionally employed magnetic recording medium comprises a non-magnetic substrate having a non-magnetic undercoat film and a magnetic film thereon; a protective film such as carbon film provided thereon; and on the protective film a lubricating film comprising a lubricant such as perfluoropolyether.
In recent years, a magnetic recording medium which can reduce spacing loss has been demanded for enhancing recording density of the medium.
A carbonaceous protective film is typically formed through sputtering. However, when a thin protective film; i.e., a protective film as thin as 100 xc3x85 or less, is produced through sputtering so as to reduce spacing loss, the film might have poor durability.
Therefore, there has been proposed a plasma CVD process which can be used to form a carbonaceous protective film having sufficient durability even when the formed film is thin.
However, in a magnetic recording medium produced through the above-described conventional technique lubricant adheres easily to a magnetic head, and fly-stiction characteristics might be deteriorated.
When fly-stiction characteristics are deteriorated, the flying stability of a magnetic head decreases, and problems such as head crush easily occur, due to contact between the protective film and the magnetic head.
Accordingly, the present invention provides a production process for a magnetic recording medium, which process comprises etching the surface of a carbonaceous protective film using plasma generated from an etching gas prior to formation of a lubricating film.
During etching of the surface of the carbonaceous protective film, high-frequency electric power may be applied to a disk on which the carbonaceous protective film is formed, to thereby generate plasma.
In the present invention, there is provided a magnetic recording medium produced through the above-described production process, where the surface of the carbonaceous protective film of the medium contains oxygen in an amount of about 2.9-12% as measured through X-ray photoelectron spectrometry.
Preferably, the carbonaceous protective film has a B/A value as defined hereinafter of about 1.22-1.65 as measured through Raman spectrometric analysis.
Alternatively, a magnetic recording medium produced through the above-described production process is provided, where the surface of the carbonaceous protective film of the medium contains nitrogen in an amount of about 5.0-16.5% as measured through X-ray photoelectron spectrometry.
Preferably, the carbonaceous protective film has a B/A value of about 1.21-1.52 as measured through Raman spectrometric analysis.